The present invention relates to an electroconductive film used for touch sensors, touch panels, and the like and relates to a touch panel and a display device which are provided with the electroconductive film. In particular, the present invention relates to an electroconductive film in which the occurrence of moire is reduced regardless of the viewing angle (observation angle) and relates to a touch panel and a display device which are provided with the electroconductive film.
Examples of an electroconductive film installed on a display unit of a display device (hereinafter, also referred to as a “display”) include electroconductive films for electromagnetic wave shields, electroconductive films for touch panels, and the like (for example, see JP 2009-117683 A and JP 2011-237839 A).
JP 2009-117683 A discloses a technique that provides a wiring pattern having excellent visibility by controlling moire frequencies based only on frequency information on a black matrix pattern and a wiring pattern of a display in forming a wiring pattern of an electromagnetic wave shielding film.
Specifically, JP 2009-117683 A discloses that a second pattern, which is generated from second pattern data in which the relative distance between spectrum peaks of two-dimensional Fourier spectra (2DFFTSp) of the respective pattern data of a first pattern such as a pixel array pattern (for example, a black matrix (hereinafter, also referred to as “BM”) pattern) of a display and the second pattern such as an electromagnetic wave shielding pattern exceeds a predetermined spatial frequency, for example, 8 cm−1, is automatically selected. JP 2009-117683 A also discloses that when the aforementioned relative distance does not exceed the predetermined spatial frequency, the operation of generating new second pattern data by changing one or more of the rotation angle, the pitch, and the pattern width of the second pattern data is repeated until the aforementioned relative distance exceeds the predetermined spatial frequency.
In this way, according to JP 2009-117683 A, it is possible to automatically select an electromagnetic wave shielding pattern that can inhibit the occurrence of moire, and that can also prevent an increase in surface resistivity and deterioration of transparency.
An electroconductive sheet for a touch panel in JP 2011-237839 A has first electroconductive portions which are formed on the main surface at one side of a substrate and second electroconductive portions which are formed on the main surface at the other side of the substrate. The first electroconductive portions extend in a first direction, are arrayed in a second direction orthogonal to the first direction, and have two or more first transparent electroconductive patterns. The second electroconductive portions extend in the second direction, are arrayed in the first direction, and have two or more second transparent electroconductive patterns. When viewed from above, the first transparent electroconductive patterns and the second transparent electroconductive patterns are arranged to cross each other and deviate in directions different from the first direction and the second direction. In this way, according to JP 2011-237839 A, a plurality of spatial frequencies are combined with each other. As a result, the interference with the pixel array of a liquid crystal display device is inhibited, and the occurrence of moire is effectively reduced.